Modified internal combustion engine

ABSTRACT

Modification of a twin opposed cylinder two-stroke internal combustion engine according to U.S. Pat. No. 3,329,134 issued in 1967 to the present inventor, which engine has a power piston reciprocating in opposed aligned power cylinders, and an effectively integral charge piston reciprocating within aligned charge cylinders, axes of the reciprocations intersecting and being perpendicular. There are no connecting rods, the power piston is journaled on a central crankpin of a crankshaft, and the effectively integral charge piston is an assembly having two elements interconnected by spaced slide blocks constrained in guides, with the slide blocks being journaled on aligned crankpins spaced from the central crankpin. The crankshaft has an unusual motion rotating about an instantaneous axis midway between axes of the central crankpin and the aligned crankpins, the instantaneous axis rotating in circular locus centered on an engine axis mutually perpendicular to the cylinder axes and passing through their point of intersection. Power takeoff is by a ring gear with internal teeth in engagement with teeth of a pinion secured to an extension of a crankshaft, giving typically a 1:3 reduction drive. Means to constrain the instantaneous axis in the locus above will effect crankshaft motion as above. In the modified engine of the present invention, discs are journaled in the frame of the engine centered on the engine axis, the discs being bored eccentrically to receive stubs at outer ends of the crankshaft, the stubs being aligned on the instantaneous axis. Thus the instantaneous axis is constrained to move in the circular locus above, effecting crankshaft motion as in the patented engine. Accordingly, the slide blocks and guides are dispensed with and the two elements of the charge piston are bolted together and journaled on the two aligned crankpins. One of the discs has a central, outwardly extending, power takeoff shaft, so that the gear train of the patented engine is also dispensed with.

Unite l States Patent Llwellyn air. M, 111978 [54] MODIFIED lNTERNAL COMBUSTION sued in 1967 to the present inventor, which engine has a ENGINE power piston reciprocating in opposed aligned power cylinders, and an effectively integral charge piston reciprocating Inventor: P y Burnaby, Bmlsh within aligned charge cylinders, axes of the reciprocations incolumbla, Canada tersecting and being perpendicular. There are no connecting rods, the power piston is journaled on a central crankpin of a [73] Asslgnee' E3 55: Engineering Vancouver crankshaft, and the effectively integral charge piston is an assembly having two elements interconnected by spaced slide [22] Filed: Oct. 1, 1970 blocks constrained in guides, with the slide blocks being journaled on aligned crankpins spaced from the central crankpin.

[21] Appl' 77216 The crankshaft has an unusual motion rotating about an instantaneous axis midway between axes of the central crankpin [30] Foreign A li ti p i Dam and the aligned crankpins, the instantaneous axis rotating in circular locus centered on an engine axis mutually perpen- Oct. 4, 1969 Great Britain ..48,868/69 dicular t the cylinder axes and passing through their point of intersection. Power takeoff is by a ring gear with internal teeth [52] US. Cl ..l23/55 R, 123/72, l23/DIG. 8 in engagement with teeth of a pinion secured to an extension [51] ..F02b 75/22, F02b 33/20 of a crankshaft, giving typically a 1:3 reduction drive.

[58] Field of Search .....l23/55 R, 72, DIG. 8 Means to constrain the instantaneous axis in the locus above 56] References Cited will effect crankshaft motion as above. In the modified engine of the present invention, discs are journaled in the frame of UNITED STATES PATENTS the engine centered on the engine axis, the discs being bored eccentrically to receive stubs at outer ends of the crankshaft,

3,175,544 3/1965 Hughes ..123/55 R the stubs being aligned on the instantaneous axis, Thus the in- 3,258,992 7/1966 Hittell ....l23/55 R stantaneous axis is constrained to move in the circular locus 3,329,134 7/ 1967 Llewellyn ..123/55 R above, effecting crankshaft motion as in the patented engine.

Primary Examiner-Wendell E. Burns Attomey-Lyle G. Trorey [57] ABSTRACT Modification of a twin opposed cylinder two-stroke internal combustion engine according to US. Pat. No. 3,329,134 is- Accordingly, the slide blocks and guides are dispensed with and the two elements of the charge piston are bolted together and journaled on the two aligned cran'kpins. One of the discs has a central, outwardly extending, power takeofi shaft, so that the gear train of the patented engine is also dispensed with.

6 Claims, 12 Drawing Figures Patented March 14, 1972 3,648,671

5 Sheets-Sheet 1 F/GS. /6- ARE PRIOR ART [3-7 45" Leopold W. Llewellyn,

v Inventor Ly 1e G. rorey Ag nt Patented March 14, 1972 3,648,671

3 Sheets-Sheet I:

Pam/e. ART

Leopold W. Llewellyn,

Inventor Lyle Trorey,

Agent Patented March 14, 1972 I 3,648,671

(5 Sheets-Sheet 5 Leopold Llewellyn,

- Lyle G. Trorey,

Agent MODIFIED INTERNAL COMBUSTION ENGINE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to internal combustion engines in (USPO) Class 123-55, and in particular to a modification of an internal combustion engine according to U.S. Pat. No. 3,329,134 issued July 4, 1967 to the present inventor, Leopold W. Llewellyn, P. Eng. Both are capable of being adapted for use as blowers.

2. Prior Art The US. patent above teaches a twin opposed cylinder twostroke internal combustion engine having a power piston reciprocating within aligned power cylinders, and a charge piston reciprocating within aligned charge cylinders, paths of the reciprocations intersecting and being mutually perpendicular. An output shaft has an axis passing through the intersection of the reciprocating paths mutually perpendicular thereto, the output shaft axis being an engine axis. The power piston has two elements secured to one another at abutting inner ends, outer ends of the elements forming piston heads. A crankshaft has a central crankpin journaled in the abutting ends of the power piston elements, the crankshaft having also two spaced, aligned, coaxial, outer crankpins. The charge piston is an assembly having two elements interconnected by spaced slide blocks secured thereto, outer ends of the elements forming piston heads. The spaced slide blocks have horizontally aligned bearings in which the two aligned crankpins rotate, and transversely spaced guides of which the blocks are slideable, being constructed and arranged so that the charge piston assembly is slideably supported by the blocks and by the charge cylinder. An extension of the crankshaft has a pinion secured thereto, the pinion being eccentric with respect to the axis of the aligned crankpins. A ring gear has internal teeth in engagement with teeth of the pinion, the ring gear being secured to the output shaft which shaft is journaled in an end wall in a housing of the enginethe pinion and ring gear being constructed and arranged so that the output shaft rotates at a speed of, typically, one third of that of the crankshaft. The engine is capable of operating on a two-stroke cycle, or a four-stroke cycle, and is adaptable to diesel operation, carburetion and/or fuel injection means being provided.

The crankshaft has an unusual motion, described as a tumbling motion. As stated, the power cylinder axis and the charge cylinder axis are mutually at right angles intersecting in the engine axis, which is normal to a plane containing the power cylinder and charge cylinder axes. The power pistons are journaled on the central crank pin of the crankshaft, consequently the engine has a mechanism such that the central pin has a straight line reciprocating motion. The charge piston is effectively journaled on the aligned crankpins which, therefore, reciprocate along the charge cylinder axis. The crankshaft has webs interconnecting the aligned crankpins with the central crankpin, consequently the crankshaft has a rotation about an instantaneous axis, the instantaneous axis passing through a web midway between the central crankpin and the aligned crankpins. As is later explained in detail, the instantaneous axis has a locus which rotates in a circular path centered on the engine axis.

SUMMARY OF THE INVENTION Since the pistons are constrained to reciprocate in co-planar paths mutually at right angles, and since the instantaneous axis above rotates in a circular path centered on the engine axis, means to constrain the instantaneous axis in the locus above will effect crankshaft motion which is the same as the tumbling motion of the engine of the US. patent. Means to effect such motion of the instantaneous axis is a central concept of the present invention.

The means include a crankshaft having a central crankpin essentially as described above, and aligned crankpins spaced equally from the central crankpin also essentially as described above, together with aligned stubs having a common axis,

being the instantaneous axis, the stubs being respectively provided at each end of the crankshaft secured by webs at outer ends of the spaced aligned crankpins. A disc is provided at each end of the crankshaft, the disc being journaled for rotation about the engine axis, each disc having an eccentric opening in which the stubs are, respectively, joumaledthe openings being spaced from the engine axis by a distance equal to the radius of the circular locus of the path of the instantaneous axis. A power output shaft is secured to one disc centrally thereof, the power shaft thus having an axis coincident with the engine axis. It is seen that structure as above effects power take-off at a 1:1 ratio and that the slide blocks and guides, and the pinion and ring gear of the patented engine are eliminated. A main purpose of the slide blocks and guides is to take up side thrust as the charge pistons approach inner ends of their strokes.

Except for speed of rotation of the output shaft, the modified engine and the patented engine are kinematically identical. The 1:1 ratio of the modified engine, and the drive structure associated therewith, permit simpler multiple cylinder versions of the engine than are readily attainable with the patented engine.

A generalized description of the patented engine related to drawings, is given below as an aid to understanding a detail description, also related to drawings, of a modified engine according to the present invention. The detail description is given by way of example, the present invention being capable of expression by means other than those particularly described and illustrated.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation, at reduced scale, of an internal combustion engine according to US. Pat. No. 3,329,134,

FIG. 2 is a section on 22 FIG. 1, showing horizontal aligned power pistons of the engine in mid position,

FIG. 3 is a section on 3-3 FIG. 2 illustrating power take-off means giving 1:3 reduction,

FIG. 4 is a section on 4-4l FIG. 1 showing one power piston in a top dead center position,

FIG. 5 is a diagram illustrating crankshaft motion,

FIG. 6 is an elevation, partly sectioned, showing an assembly of a charge piston and slide blocks to the crankshaft.

FIGS. 1-6 are prior art, the crankshaft motion illustrated in FIG. 5 being also attained in an internal combustion engine according to the present invention.

FIG. 7 is an elevation of a crankshaft of the engine of the present invention,

FIGS. 8 and 9 are respectively sections on 8-8 and 99 FIG. 7,

FIG. 10 is an assembly of the crankshaft FIG. 7 to charge and power pistons of the engine of the present invention,

FIG. 11 is a section on 11-11 FIG. 10, with relative posi tion of the crankshaft being added and shown in broken outline.

FIG. 12 shows a multiple cylinder version of the modified engine.

GENERALIZED DESCRIPTION OF THE PATENTED ENGINE FIGS. 1, 2 AND 3 References to left, right, top, and bottom refer to the engine as viewed in FIG. 41.

The engine 1111 according to the patent above has aligned horizontally opposed left and right power cylinders 11, 12, and vertically opposed aligned top and bottom charge cylinders 13, 14. The engine has a main axis X and a power cylinder axis Y, the X and Y axes are coplanar of a horizontal plane and at right angles intersecting in a charge cylinder axis Z, which axis is vertical.

A power piston has two elements 15, 16 with abutting inner ends secured to one another by bolts 17 so as to be effectively integral, the power piston being journaled on a central crankpin 18, broken outline in FIG. 2, of a crankshaft, so that the pistons reciprocate with the central crankpin having lineal reciprocating motion, being simple harmonic motion, on the Y-axis.

FIGS. 4 AND 6 Referring particularly to FIGS. 4 and 6, the charge cylinders have upper and lower piston elements 19 and 21 with inner ends bolted to spaced rectangular slide blocks 23 and 24, with aligned crankpins 26, 27 of the crankshaft joumaled in the spaced slide blocks as shown in FIG. 6. The crankshaft is designated generally 25 and has the central crankpin l8 aforesaid, with integral webs 29 extending from the central crankpin 18 to the aligned crankpins 26, 27 as shown. The charge piston elements being bolted, respectively, to outer ends of the slide blocks, the charge piston too is effectively integral. The aligned crankpins have extensions 31 and 32.

DRIVE, FIGS. 1 AND 3 A flanged housing 33 is concentric with the engine axis X, a drive shaft 34 extends externally through the housing, the shaft having a centerline coincident with the engine axis X, and an inner end within the housing. A ring gear 35 having internal teeth is secured to the inner end of the shaft, and an eccentric pinion 36 is keyed to the crankpin extension 32 (FIGS. 3 and 6), the pinion having teeth engaging the ring gear 35. Thus rotation of the crankshaft drives the drive shaft 34 at, in the particlar engine illustrated, a 1:3 speed reduction.

CRANKSI-IAFT MOTION, FIG.

As indicated diagrammatically in FIG. 5, the essentially integral power piston elements 15, 16 reciprocate along the Y- axis with the essentially integral charge piston elements reciprocating on the Z-axis. With the crankshaft having constant angular velocity throughout a complete revolution, these motions would be simple harmonic, having a phase relationship indicated in solid and broken outline in FIG. 5.

It is clear from FIG. 4 that the central crankpin 18 reciprocates along the Y-axis (as viewed in FIG. 5) and it is clear from FIG. 4 and FIG. 6 that, the slide blocks having straight line reciprocating motion, the aligned crankpins 26, 27, also have simple harmonic reciprocating motion along the Z-axis (as viewed in FIG. 5). Consequently, the locus of a point between 27 and 18 FIG. 5, on a straight line between 27 and 18 FIG. 5, varies between a limit, when the point is coincident with 27, of straight line motion along the Z-axis, through motion in an ellipse having a major axis on the Z-axis when the point is adjacent 27, an ellipse having a major axis coincident with the Y-axis when the point is adjacent l8, and a straight line along the Y-axis when the point is coincident with 18. A point in a position D midway between 27 and 18 will thus have a circular locus, the circle having a center at the intersection of the Y and Z axes, that is to say on the X-axis with which the centerline of the output shaft is coincident. D defines an instantaneous axis about which the crankshaft also revolves.

ALTERNATIVE DRIVE ACCORDING TO THE PRESENT INVENTION Travel of the point D in a circular path is utilized, in the present invention, to eliminate the slide blocks 23 and 24 and to provide a 1:1 drive ratio with simpler construction than that taught in the U.S. Pat. No 3,329,134.

This is accomplished by providing a modified crankshaft having stubs centered at D FIG. 5, and by mounting a disc houmalled in the flanged housing 33. With the stubs joumaled in an opening of the disc, it is seen that rotation of the crankshaft rotates the disc about the engine centerline X-X so that the drive shaft 34, being central of the disc, is driven at 1 to l by rotation of the crankshaft. Since the aligned crankpin 27, FIG. 5, and the aligned crankpin 26, have straight line motion, the slide blocks can be dispensed with and the essentially integral charge pistons 19 and 21 are joumaled on aligned crankpins of a modified crankshaft. It is seen that relative motions of a power and charge pistons are unchanged kinematically by this arrangement.

Structure to effect the foregoing is described in detail below, being means co-operating with outer ends of the crankshaft to effect restraint of the virtual axis in a circular locus.

DETAIL DESCRIPTION OF THE PRESENT INVENTION MODIFIED CRANKSI-IAF'T, FIGS. 7, 8, 9

A crankshaft modified according to the present invention is designated generally 40, having a central crankpin 41 generally equivalent to the crankpin 18 FIG. 6, and aligned crankpins 42 and 43 generally equivalent to the aligned crankpins 26, 27 FIG. 6. Stubs 44 and 45 are provided at outer ends of the crankshaft, the stubs having a centerline or the instantaneous axis at the position D FIG. 5. Webs 46 and 47 extend from the stubs 44 and 45 to the aligned crankpins 42 and 43 as shown, with webs 48, 49 joining ends of the aligned pins 42, 43, to the central crankpin 41 as shown.

FIG. 10

FIG. 10 shows an assembly of the crankshaft 40 to the discs and to output shafts. The discs, 51 and 52, are bored eccentrically to accept the crankshaft stubs 44 and 45 joumaled therein in roller bearings 53 and 54. The discs 51 and 52 have aligned axes coincident with the engine axis X. A flanged housing 55 is provided at each end of the crankshaft, only one housing being shown in FIG. 10. The housing 55 is generally similar to the housing 33 FIGS. 1 and 2, being circular and having a center on the engine axis X. Output shafts 56, here shown as integral with the eccentric discs 51 and 52 respectively, have common axes aligned with the engine axis X, one I output shaft extending through the housing 55 as shown.

The flanged housings 55 have machined inner cylindrical surfaces to accept outer races of roller bearings 57, inner races of which accept the discs 51 and 52.

Since the aligned axes of the stubs are at the position D FIG. 5, and since the discs 51 and 52 are centered on the engine X axis, with the bearings 53 and 54 having centers at a distance from the engine axis X equal to the distance of D FIG. 5 from the engine axis X, it is clear that structure according to FIG. 10 effects motion of the crankshaft as previously described with reference to FIG. 5, and as in the patented engine, without necessity for slide block and guide restraint.

Charge pistons 58 and 59 have skirts 61 and 62 bolted together (the bolts not being shown in FIG. 10) so as to be essentially an integral skirt. The charge pistons reciprocate within opposed charge cylinder as described with reference to the cylinders 13 and 14. The integral skirt has an opening defined by side walls 63 as shown, the opening being constructed and arranged to provide clearance for the rotating webs 48 and 49. Power pistons are indicated diagrammatically at 64, and are as before described with reference to the internal combustion engine of the U.S. patent, being joumaled directly in the central crankpin 41 as before described with reference to the crankpin 18 FIG. 4 and adapted to reciprocate within opposed power cylinders as described with reference to the cylinders 11 and 12. It is clear that positions of the power pistons and the charge pistons can be reversed, that is to say the power pistons can be joumaled on the aligned crankpins 42 and 43, with the charge pistons joumaled on the central crankpin 41.

Two output shafts are shown in FIG. 10, one can be dispensed with. Further details of the internal combustion engine according to the present invention are not described in detail since the present invention, considered in relation to the U.S. patent, has now been disclosed.

MULTI-CYLINDER VERSIONS OF THE MODIFIED ENGINE FIG. 12 In FIG. 12, an engine a according to the present invention is designated 70 having a right hand output shaft 71 and a right hand disc 72 as before described. Right and left aligned stubs 73 and 74 engage respectively the right disc 72 and a left disc 75, the engine axes of both engines being aligned.

As second engine according to the present invention is designated 50 having left and right aligned stubs 511 and 52. The disc 75, in addition to receiving the stub 74 of the engine 70, is also adapted to receive the stub 82 of the engine 80. The disc 75 has diametrically opposite openings to receive the stub 82 of the engine 40 as well as the stub 74 of the engine 70, thus the disc 75 of the engine 70 is common to both engines, the stubs 32 and 74 both being journaled therein.

Referring to the engines 70, it is apparent that rotation of its crankshaft will rotate the disc 75 as before explained. Referring to the engine 30, it is also apparent that rotation of its crankshaft will also rotate the disc 75 in the same direction, the engines 70 and 50 thus work in tandem, with power pistons of each being 180 out of phase.

It is evident that a third, and additional, engines could be added in tandem.

It is seen that the power cylinders of the engines 70 and 80 FIG. 12 are aligned, it is clear that they could be placed at right angles by providing an opening (not shown) in the common disc 75 at 90, or 270', from the stub 74-rather than diagrammetrically opposite or at 180 as shown. Many configurations are seen to be possible, and it is also apparent that in a multi-cylinder engine of this nature cylinder blocks, or cylinder block units, can be integral.

It is particularly to be noted that the two crankshafts in FIG. 12 are separate entities but are, within the limits of machining tolerances, identical so as to be interchangeable. Depending upon the particular cylinder arrangement, there are many balancing possibilities of multi-cylinder engines of this general kind. A further factor of importance is that the separate crankshaft construction has manufacturing advantages, and a practical advantage in that some difficulties associated with long, multi-bearing, crankshafts are avoided.

lclaim:

11. An internal combustion engine having: a housing; a power piston (64) reciprocating on a Y-axis within opposed power cylinders (ill, 12); a charge piston (55, 59) reciprocating within opposed charge cylinders (13, 14) on a coplanar Z- axis intersecting the Y-axis at right angles; a crankshaft (40) having outer ends; the power pistons being journaled on a central crankpin (4ll) of the crankshaft (40); the charge piston being joumaled on aligned crankpins (42, 43) spaced equally either side of the central crankpin; the crankshaft having rotation about an instantaneous axis (D) normal to the plane containing the Y and Z axes and being coplanar with and midway between axes of the central crankpin and the aligned crankpins; the engine being characterized by:

means cooperating with the outer ends of the crankshaft to effect restraint of the virtual axis in a circular locus.

2. An engine according to claim l, and an output shaft (56) having a centerline on an X or engine: axis mutually perpendicular to the Y and Z axes and passing through their point of intersection.

3. An engine according to claim 11, the means to effect restraint of the virtual axis including,

a. a stub (44, 45) at each end of the crankshaft, the stubs having a centerline on the instantaneous axis,

b. webs (46, 47) extending from the stubs to the aligned crankpins,

c. discs (51, 52) bored eccentrically to accept the stubs, the

discs being journaled in the housing on an engine or X- axis mutually perpendicular to the Y and Z axes, and passing through their point of intersection, so that the instantaneous axis travels in a circular path being the locus aforesaid.

4. An engine according to claim 3 wherein,

d. at least one disc has an output shaft 56 having a center line on the X-axis.

5. An engine according to claim 4 being a first engine and a second similar engine (80), and means interconnecting the engines with their engine axes aligned, and the power pistons of each engine 1 80 out of phase.

6. An engine according to claim 4, being first engine (70),

having a right hand output shaft (711) and a right hand disc (72), and a left disc with right and left aligned stubs (73, 74) engag'ng respectively the right and left discs; and a second similar engine having left and right aligned stubs (M, 52); the left disc (75 of the first engine being also adapted to receive the right stub (52) of the second engine having diametrically opposite openings receiving the stubs, the left disc (75) of the first engine being common to both engines, the engine axes being aligned.

h 4: l 4K 

1. An internal combustion engine having: a housing; a power piston (64) reciprocating on a Y-axis within opposed power cylinders (11, 12); a charge piston (58, 59) reciprocating within opposed charge cylinders (13, 14) on a coplanar Z-axis intersecting the Y-axis at right angles; a crankshaft (40) having outer ends; the power pistons being journalled on a central crankpin (41) of the crankshaft (40); the charge piston being journalled on aligned crankpins (42, 43) spaced equally either side of the central crankpin; the crankshaft having rotation about an instantaneous axis (D) normal to the plane containing the Y and Z axes and being coplanar with and midway between axes of the central crankpin and the aligned crankpins; the engine being characterized by: means co-operating with the outer ends of the crankshaft to effect restraint of the virtual axis in a circular locus.
 2. An engine according to claim 1, and an output shaft (56) having a centerline on an X or engine axis mutually perpendicular to the Y and Z axes and passing through their point of intersection.
 3. An engine according to claim 1, the means to effect restraint of the virtual axis including, a. a stub (44, 45) at each end of the crankshaft, the stubs having a centerline on the instantaneous axis, b. webs (46, 47) extending from the stubs to the aligned crankpins, c. discs (51, 52) bored eccentrically to accept the stubs, the discs being journalled in the housing on an engine or X-axis mutually perpendicular to the Y and Z axes, and passing through their point of intersection, so that the instantaneous axis travels in a circular path being the locus aforesaid.
 4. An engine according to claim 3 wherein, d. at least one disc has an output shaft (56) having a centerline on the X-axis.
 5. An engine according to claim 4 being a first engine (70) and a second similar engine (80), and means interconnecting the engines with their engine axes aligned, and the power pistons of each engine 180* out of phase.
 6. An engine according to claim 4, being first engine (70), having a right hand output shaft (71) and a right hand disc (72), and a left disc (75) with right and left aligned stubs (73, 74) engaging respectively the right and left discs; and a second similar engine (80) having left and right aligned stubs (81, 82); the left disc (75) of the first engine being also adapted to receive the right stub (82) of the second engine having diametrically opposite openings receiving the stubs, the left disc (75) of the first engine being common to both engines, the engine axes being aligned. 